Feeding mechanism

ABSTRACT

A feeding mechanism. The feeding mechanism comprises a roller and a blocking plate. The blocking plate rotates between a first position and a second position, abutting a sheet when in the first position, and the sheet sliding thereon by gravity when in the second position. Particularly, the blocking plate and the sheet form an included angle larger in the first position than in the second position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a feeding mechanism, andmore particularly, to a feeding mechanism having a rotatable blockingplate capable of positioning media sheets precisely.

2. Description of the Related Art

Generally, conventional business machines, such as printers, have amedia positioning device keeping sheet media in a predetermined positionsuch that the sheets can be fed smoothly. Referring to FIG. 1 a, aconventional feeding mechanism has an arm 1, a movable restraint 2 and atray 20, wherein a roller 10 is disposed at the end of the arm 1. Whenthe arm raises and the roller 10 leaves the sheets S, the restraint 2lifts and abuts the sheets S in a predetermined position. When feedingthe sheets S, as shown in FIG. 1 b, the restraint 2 lowers such that theroller 10 contacts and drives the sheets S.

As mentioned, the restraint 2 abuts the sheets S in a predeterminedposition, however, multiple sheets may be fed, or improperly fed.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a feedingmechanism capable of positioning media sheets precisely, preventingmultiple sheets intake and improper feed. The feeding mechanismcomprises a roller and a blocking plate. The blocking plate rotatesbetween a first position and a second position, abutting a sheet in thefirst position, and the sheet sliding thereon by gravity in the secondposition. Particularly, the blocking plate and the sheet form anincluded angle larger in the first position than in the second position.

DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawings,given by way of illustration only and thus not intended to be limitativeof the present invention.

FIG. 1 a and 1 b are perspective diagrams of a conventional feedingmechanism.

FIG. 2 a and 2 b are perspective diagrams of a feeding mechanism inaccordance with the present invention.

FIG. 2 c, 2 d and 2 e are perspective diagrams of a blocking platerotating between the first and second positions in accordance with thepresent invention.

FIG. 3 a is a perspective diagram of a shaft rotating a cam inaccordance with the present invention.

FIG. 3 b is a perspective diagram of a cam in accordance with thepresent invention.

FIG. 4 a is a perspective diagram of the cam rotating counterclockwiseto a maximum position.

FIG. 4 b is a perspective diagram of the cam rotating clockwise to amaximum position.

FIG. 4 c is a perspective diagram of the blocking plate returning to thefirst position.

DETAILED DESCRIPTION OF THE INVENTION

An object of the present invention is to provide a feeding mechanismpreventing multiple sheets intake and improper feed. Referring to FIG. 2a, the feeding mechanism is applied to a business machine, such as aprinter or a scanner, has a roller R, a shaft L, a movable blockingplate 30, a cam 4, a tray 5 and a cover 6. The blocking plate 30 isconnected to a torsion spring 31 and is rotatable between a firstposition 3 and a second position 3′. The roller R is fixed to the shaft,and the cam 4 has a depression 410 and is rotatable on the shaft L. Whenin the first position 3, as shown in FIG. 2 a, the blocking plate 30abuts the cam 4 in the depression 410. Moreover, to feed the sheets S,the cam 4 rotates around the shaft L clockwise such that the blockingplate 30 is pushed down to the second position 3′. Subsequently, thesheets S on the tray 5 are driven by the roller R. As shown in FIG. 2 b,the shaft L is fixed to the cover 6 and passes through the roller R andthe cam 4. When the cover 6 opens, the cam 4 and the roller R areseparated from the blocking plate 30, and the blocking plate 30 isreturned to the first position 3 by the torsion spring 31.

Referring to FIG. 2 c, when in the first position 3, the blocking plate30 is approximately perpendicular to the sheets S, wherein the sheets Sslide down and abut the blocking plate 30 by gravity. In FIG. 2 d, whenthe blocking plate 30 shifts to the second position 3′, the sheets S andthe blocking plate 30 form an obtuse angle such that the sheets Sspontaneously slide on the smooth surface of the blocking plate 30 bygravity.

Particularly, when the blocking plate 30 rotates from the first position3 to the second position 3′, the upper sheets S slip a larger distancethan the lower sheets S due to less frictional force and higher velocitytransferred from higher potential energy. Thus, as shown in FIG. 2 d,the upper sheets S spontaneously progress forward by gravity to be fedproperly. The staggered sheets S are loose and capable of being fedwithout accidental feeding of multiple sheets.

FIG. 2 e shows the blocking plate 30 rotating between the first position3 and the second position 3′, wherein the torsion spring 31 exerts aforce returning the blocking plate 30 to the first position 3. Referringto FIGS. 3 a and 3 b, the shaft L passes through the roller R, the cam 4and the driving assembly D, wherein the driving assembly D rotates thecam 4. The driving assembly D has a frictional member F, a spring P anda fixed portion E fixed to the shaft L. When the shaft L rotates theroller R and the driving assembly D, the cam 4 is driven by thefrictional force between the frictional member F and the cam 4.

The cam 4, as shown in FIG. 3 b, has a contacting portion 41, arestraining portion 42 and a through hole 40 through which the shaft Lpasses. The contacting portion 41 has a depression 410 disposed thereonand rotates the blocking plate 30 between the first position 3 andsecond position 3′. Moreover, the restraining portion 42 has aprotrusion 421 restricting the cam 4's rotation to within a limitedrange. Referring to FIGS. 4 a and 4 b, when the cam 4 rotatescounterclockwise to a maximum position, the protrusion 421 ofrestraining portion 42 abuts the protruding restraint 61 of the cover 6,wherein the blocking plate 30 is located in the depression 410 and thefirst position 3. Thus, the sheets S are precisely positioned on thetray 5.

To feed the sheets S, as shown in FIG. 4 b, the shaft L rotates theroller R, the driving assembly D and the cam 4 clockwise, wherein thecam 4 pushes the blocking plate 30 to the second position 3′and theprotrusion 421 abuts the restraint 61. Particularly, if the shaft Lfurther rotates the roller R and the driving assembly D beyond themaximum position, the cam 4 is held with the frictional member 421sliding thereon, and the spring P provides elastic force such that thefrictional member 421 contacts and slides with respect to the cam 4.Thus, the roller R feeds the sheets S properly.

After feeding the sheets S, the shaft L rotates the cam 4 and thedriving assembly D counterclockwise to the maximum position as shown inFIG. 4 c. Thus, the protrusion 421 abuts the restraint 61 such that thecam 4 is restricted preventing obstruction of the blocking plate 30. Insummary, the present invention provides a feeding mechanism having amovable blocking plate 30 capable of positioning media sheets precisely,preventing multiple sheets intake and improper feed.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it is to be understood that the invention isnot limited to the disclosed embodiments. To the contrary, it isintended to cover various modifications and similar arrangements (aswould be apparent to those skilled in the art). Therefore, the scope ofthe appended claims should be accorded the broadest interpretation toencompass all such modifications and similar arrangements.

1. A feeding mechanism, comprising: a roller; and a blocking plate,rotating between a first position and a second position, abutting amedia sheet in the first position, and the sheet sliding on the blockingplate by gravity in the second position, wherein the blocking plate andthe sheet form an included angle larger in the first position than inthe second position.
 2. The feeding mechanism as claimed in claim 1further comprising a torsion spring connected to the blocking plate,around which the blocking plate rotates.
 3. The feeding mechanism asclaimed in claim 1, wherein the blocking plate is substantiallyperpendicular to the sheet in the first position.
 4. The feedingmechanism as claimed in claim 1, wherein the torsion spring provides aforce driving the blocking plate to the first position.
 5. The feedingmechanism as claimed in claim 1 further comprising a shaft and a cam,wherein the cam rotates around the shaft and rotates the blocking platebetween the first and second position.
 6. The feeding mechanism asclaimed in claim 5, wherein the cam comprises a depression with theblocking plate located therein when in the first position.
 7. Thefeeding mechanism as claimed in claim 5 further comprising a drivingassembly comprising a fixed portion and a frictional member, wherein thefixed portion connects to the shaft, and the frictional member contactsand rotates the cam.
 8. The feeding mechanism as claimed in claim 7,wherein the driving assembly further comprises a spring connecting thefixed portion and the frictional member.
 9. The feeding mechanism asclaimed in claim 5 further comprising a restraint fixed thereto, whereinthe cam has a protrusion abutting the restraint when the cam rotates toa maximum position.
 10. The feeding mechanism as claimed in claim 9further comprising a driving assembly having a fixed portion and africtional member, wherein the fixed portion connects to the shaft, andthe frictional member slides on the cam when the cam rotates beyond themaximum position.